Wow, I'm SOO looking forward to next months. LOT'S of great things will happen.. as for Braixen making it into Pokken.. it's interesting. A bit wierd, but interesting. I like how they pull out some certain pokemon nobody expected to be in this game, like Suicune, Gardevoir. Though this makes me think if Chesnaught will ever make it in..? If not, I really expect to see the Kalos starters get some "special treatment" in "Z".
And with all these events happening next month, it gives me a shimmer of hope of a main game announcement could be in the works.. either by some sudden hint in the Super bowl ad along with GO, or sometime after the 27th (since they want to show the best for last) either way, I don't expect CC to reveal it.. even though I wouldn't mind it at all, GF probably wants the fans to try out the VC, and that announcement would make alot of fans be anxiously waiting for "Z" to come out more than anything else.
But movie-wise, I expect Volcanion to have a form, and expect Zygarde to make a role in this movie since the info on Volcanion in the official website states: "It uses fire and water to create steam within its body, expelling explosive shock waves and boiling steam from the arms on its back. The power is said to be great enough to blow away an entire mountain, gouging out the earth and changing the shape of the land." That alone makes Zygarde fitting enough to stop it.
That being said, I think Volcanion's concept could be expanded to include multiple forms based on different power sources. This lines up very nicely with the locked doors in the Power Plant, which carries a similar theme. Going off that, the new forms would probably be Fire/Grass, Fire/Electric, Fire/Flying, and Fire/Ground.
How was it created? It could be definitely a Pyroar that was artificially modified by Team Flare, fitted with that "special" organ, powered by Infinity Energy. Volcanion has a cat-like face, it shares a color scheme or red and yellow and also the same eye color as Pyroar, and since you could assume Pyroar is Lysandre's favorite Pokémon, I believe you could assume he started experimenting on one, perhaps with the original purpose of creating the ultimate partner and saving people with such immense power, like he wanted to before, but instead it goes badly and turns out doing the opposite, similarly with the Ultimate Weapon and his and AZ's intentions with it.